Wisconsin Governor Jim Doyle has decided against seeking a third term in 2010, the AP reported. Doyle's decision is expected to be announced on Monday. His departure may signal the end of a pro-gay administration in Madison.

Gay and lesbian couples in Wisconsin won a victory when Doyle included a domestic partnership law in his biannual state budget and lawmakers approved it. Despite an ongoing legal challenge mounted by social conservatives, the registry opened this month. So far, about 440 couples have signed up for the registry that grants about 43 rights, most of which center around estate planning and hospital visitation issues.

Doyle's announcement comes as he faces souring approval numbers after raising taxes and fees to help plug a $6.6 billion budget deficit. Giving Republicans a strong shot at regaining the state's top office.

The top two Republican candidates vying to replace Doyle, Milwaukee County Executive Scott Walker and former Rep. Mark Neumann, oppose granting gay men and lesbians the right to marry.

During his two terms in Congress, Neumann voted in favor of Georgia Representative Bob Barr's Defense of Marriage Act (DOMA), the 1996 law that allows states to ignore legal gay marriage and defines marriage as a heterosexual union for the federal government.

In 2005, Walker strongly advocated for placing a constitutional amendment banning gay marriage in Wisconsin's Constitution: “Many years ago, I concluded that we must change the Wisconsin State Constitution to say that marriage is to be between one man and one woman. … My belief in this position is even stronger today,” Walker said in a statement. The next year, voters approved the measure.

Expected Democratic candidates – including frontrunner Lt. Governor Barbara Lawton – are gay friendly. Lawton opposed the state's ban on gay marriage.

Another candidate, Congressman Ron Kind, scores high marks from the Human Rights Campaign, America's largest gay rights advocate. Kind scored 85 points out of 100 in HRC's latest scorecard on GLBT rights.

Politico reports that Doyle may be eyeing an Obama administration appointment, a move that would put Lawton in the governor's mansion before next year's election.